The number of U.S. mass layoffs rose 11.8% in September compared with the same month last year on a seasonally adjusted basis, and the initial claims for unemployment insurance related to mass layoffs rose 3.0%, the U.S. Bureau of Labor Statistics reported today.

In September, there were 2,561 mass layoff actions compared with 2,290 in September 2008. There were 248,006 associated initial claims for unemployment insurance in September compared with 240,721 in the same month last year.

Temporary help services was the industry with the largest number of initial claims for unemployment benefits from mass layoffs in September with 5,635 claims.

A mass layoff action involves at least 50 workers from a single workplace.